Hi all,

not sure whether 32/64 bit is the right direction to go. I had the same problem with PowerPoint and it seemed to have been a problem with const not being declared private (where possible). I do have (public) const in my project and they work. Only additional constants that were added later and used only in the respective modules seem to have caused the trouble. Maybe 64 bit is only aggravating a different cause?

Quite weird: you test, compile and save the project in either version (2007/2010) and you cannot open it with the other without code being dismissed. Always the same module(s), different starting lines though. And the other modules had constants added later, too. So why do some modules fault while others don't? And why consistently the same modules? (Though I have to admit having had variations such that two modules faulted at the beginning. After I had restructured the project to isolate code only one module faulted. However after implementing test results (only minor changes), another module started to fault, too. Ever since it had been these two modules and after declaring constants private whereever possible, I was able to open the project in both PowerPoint versions crosswise. Luckily! I hope this is a stable solution ;-)

As the code is working fine in both versions of PowerPoint, I would not have expected any incompatibility if that's the right word to use for this trouble. So how does PowerPoint 2010 save (or open) VBA projects differently from 2007? Does anyone have technical information on that? Or has a suggestion where to search? (In case I am encountering the problem again.)